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Skylights Melbourne Supply & Installation
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Replace old skylight domes
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VELUX FCM 4646 Flat Roof Skylight 1275x1275mm

Original price was: $749.28.Current price is: $621.90.

The VELUX FCM 4646 Fixed Skylight is a premium oversized skylight designed to maximise natural daylight in large living areas, architectural homes, and expansive open-plan spaces. Featuring high-performance double glazing, excellent thermal efficiency, and a sleek low-profile design, it creates brighter, more inviting interiors while helping reduce energy consumption. Built to withstand Australian conditions, the VELUX FCM 4646 delivers exceptional durability, modern aesthetics, and outstanding daylight performance for Melbourne homes.

Planning a skylight project? Get expert advice, check current stock and receive an exclusive Discount Code instantly by SMS. Offer ends 30/9/26. Call 0413 922 958 for urgent orders.
✔ Velux Supply & install ✔ Custom flashing available   ✔ Noble Park showroom pickup   ✔ 2026 Cost Guide  ✔ Custom Flashing Guide

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Get a special Discount Code to your mobile instantly so you can have a further discount up to 5% extra on every item on our store.

Description

The VELUX FCM 4646 Flat Roof Skylight 1275x1275mm is a large fixed glass skylight for flat and low-pitch roofs from 0–60°. With a generous 1181x1181mm visible glass size and approximately 1.40m² daylight area, it creates a premium square daylight feature for living rooms, kitchens, dining areas, large bathrooms, stairwells and open-plan extensions. Its high-performance double glazing includes toughened outer safety glass, laminated inner safety glass, Low-E coating, argon gas cavity and NEAT™ coating for comfort and reduced cleaning.

For correct waterproofing, pair it with the suitable custom flashing for VELUX FCM 4646. For ventilation, compare the matching VCM 4646 manual opening model or VCS 4646 solar opening model. Browse the VELUX FCM range or request a supply and install quote.

14 reviews for VELUX FCM 4646 Flat Roof Skylight 1275x1275mm

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    Egbert Valerie –

    Reliable products with full confidence in their leak-proof performance.

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    Andrew Edward –

    Good quality

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    Aneurin Arnold –

    How nice it is!

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    Basil A –

    The fit is excellent, and the quality is impressive. Central Skylights delivered our skylight incredibly quickly. I’ll definitely be ordering from them for the next time

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    Cuthbert –

    the shipping is very fast, thanks

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    Erastus –

    Simple to install and functions perfectly.

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    Orborne W –

    Premium skylights that promise durability and elegance. I’m confident we’ll appreciate them for years to come

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    Eugene W –

    Perfect fit and very beautiful! Thanks!

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    Cyrus B –

    Installed effortlessly and went up perfectly

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    Tadhg G –

    It arrived exactly as expected, thanks

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    Wilfred Z –

    Perfect fit and no leaks any more

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    Dalziel –

    The glass arrived in perfect condition, along with the flashing. This 4×4 is quite heavy, so be sure to have some help when lifting it into position. The installation process was relatively straightforward.

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    Egbert –

    I’ve been using Velux skylights for years, and they always deliver.

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    Oscar J –

    Great product! The new skylight blended perfectly with the curb, and I secured it in place with the supplied screws.

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V

VELUX Premier Dealer

Genuine VELUX skylights supplied by a Melbourne VELUX specialist.

M

Melbourne supply & install

Supply-only, delivery, pickup or complete installation options available.

N

Pickup from Noble Park

Convenient local pickup from our Noble Park showroom and warehouse.

12k

12,000+ installations

Experienced skylight team with thousands of Melbourne installations completed since 2018.

Product details

VELUX FCM 4646 Flat Roof Skylight 1275 x 1275mm

The VELUX FCM 4646 is a large square fixed flat roof skylight designed for premium daylight impact. Its 1275 x 1275mm frame and 1181 x 1181mm visible glass area create a strong, balanced sky view for living rooms, kitchens, dining areas, studios, large bathrooms and open-plan extensions where a standard skylight may not provide enough natural light.

Key product details

Product size 1275 x 1275mm
Internal glass size 1181 x 1181mm visible glass size.
Daylight area Approximately 1.40m² visible glass area, before any internal shaft or lining effect.
Approx. weight 41.91kg excluding flashing. Plan lifting access, roof access and safe handling before installation.
Suitable roof type Flat and low-pitch roof applications where a suitable kerb/upstand and custom flashing detail can be used.
Roof pitch Suitable for roof pitches from 0° to 60°, subject to correct installation and waterproofing. A slight pitch is recommended where possible to reduce water ponding.
Flashing required Requires custom-made flashing, sold separately. See the matching custom flashing for VELUX FCM 4646.
Related opening models Need ventilation instead of fixed daylight? Compare the VCM 4646 manual opening skylight or the VCS 4646 solar opening skylight.
Best rooms Living rooms, kitchens, dining spaces, large bathrooms, stairwells, studios, open-plan extensions and feature daylight areas.

Best suited for

The FCM 4646 is best used where you want a generous square daylight feature rather than a small spot of light. It can brighten a large living area, create a premium sky-view moment above a kitchen or dining zone, or give a flat-roof extension a more open, architectural feel.

Because this is a large glass skylight, it needs proper planning around roof structure, kerb size, lifting access, water direction, flashing design and internal ceiling layout.

Large square skylight Flat roofs Fixed glass skylight Premium daylight feature Custom flashing

Need to compare nearby sizes? View the full VELUX FCM flat roof skylight range.

Need ventilation?

Related opening models for the same 1275 x 1275mm size

The FCM 4646 is fixed and does not open. If the room needs airflow, humidity control or automatic rain-sensor closing, compare these opening flat-roof skylights in the same size family.

Manual opening

VELUX VCM 4646 Manual Opening Skylight

A cost-effective opening option for flat roofs where natural ventilation is required. It includes an insect screen and can be operated by handle or control rod depending on reach and installation position.

Solar opening

VELUX VCS 4646 Solar Opening Skylight

A premium solar-powered opening option with remote control, rechargeable battery operation, insect screen and rain sensor that automatically closes the skylight when rain is detected.

Model guide

About this VELUX FCM model

About the VELUX FCM 4646

The VELUX FCM 4646 flat roof skylight is a fixed glass skylight made for large, balanced daylight. Its square shape gives a wide and even light spread, making it ideal for rooms where the skylight is intended to be a visual feature as well as a practical daylight source.

Compared with older acrylic or polycarbonate dome skylights, the FCM 4646 gives a cleaner low-profile finish, premium glass appearance and modern VELUX glazing performance.

Fixed vs opening options

The FCM 4646 is a fixed, non-opening skylight. It is best when the main goal is daylight, sky view and a clean ceiling feature.

If the room needs ventilation, compare the VCM 4646 manual opening model or the VCS 4646 solar opening model. For daylight only, the FCM 4646 keeps the system simpler and more cost-effective.

Supply only vs installed

Central Skylights can supply the FCM 4646 for pickup from Noble Park, arrange Melbourne delivery where available, or help with a complete supply-and-install option for suitable projects.

Supply-only suits builders, roofers and renovators who already have trades arranged. Homeowners often prefer full installation for a large skylight like this, especially where lifting, custom flashing, shaft framing and plaster work need coordination.

Melbourne installation notes

A large flat roof skylight needs careful planning around roof fall, kerb height, roof profile, water direction, sheet layout and flashing design. The square 1275 x 1275mm size should be positioned so the external waterproofing and internal ceiling finish both work properly.

Before ordering, confirm roof type, access, roof pitch, roof framing and whether the skylight will sit above a flat ceiling, raked ceiling or plaster shaft.

More information

Specifications, installation notes and FAQs

Specifications
  • Model: VELUX FCM 4646
  • Product type: Fixed flat roof skylight
  • Operation: Fixed / non-opening
  • Overall external frame size: 1275mm x 1275mm
  • Visible glass size: approximately 1181mm x 1181mm
  • Approximate daylight area: approximately 1.40m² visible glass area
  • Approximate skylight weight: 41.91kg excluding flashing
  • Roof pitch: suitable for 0° to 60° roof pitch when correctly installed
  • Orientation: can be installed in portrait, landscape or diamond orientation where roof structure and flashing allow
  • Glazing: VELUX high-performance double glazing with toughened outer glass, laminated inner safety glass, Low-E coating and argon gas cavity
  • Glass coating: NEAT™ coating helps reduce dirt build-up, water spotting and cleaning frequency
  • Flashing: custom flashing required and sold separately
  • Related opening models: VCM 4646 manual opening and VCS 4646 solar opening
Installation notes
  • The FCM 4646 should be installed on a suitable kerb/upstand with correct waterproofing around the skylight.
  • Custom flashing is required and should be matched to the roof profile, pitch, drainage direction and site conditions.
  • A slight pitch is recommended where possible to help reduce water ponding on the glass.
  • Because this is a large and heavier glass unit, lifting access, roof access and safe handling should be planned before installation.
  • Check roof structure, rafters, battens, roof sheets and ceiling joists before confirming the opening location.
  • Interior finishing may require shaft framing, plastering and sanding depending on ceiling height and roof cavity depth.
  • For acrylic dome replacement, measure the existing throat size, kerb size and roof condition before confirming compatibility.
Delivery & pickup
  • Pickup may be available from Central Skylights in Noble Park.
  • Melbourne delivery may be available depending on stock, location, order size and timing.
  • Because of its size and weight, handling and unloading should be planned before delivery or pickup.
  • Custom flashing is usually ordered separately and may have a different lead time from the skylight.
  • Builders, roofers and renovators can order supply-only.
  • Homeowners can request help choosing the correct skylight size, flashing and installation option before ordering.
FAQs

Is the VELUX FCM 4646 suitable for a flat roof?

Yes. The FCM 4646 is designed for flat and low-pitch roof applications when installed with a suitable kerb/upstand and correct custom flashing.

Does the FCM 4646 open?

No. This is a fixed skylight designed for daylight only. If the room needs ventilation, compare the VCM 4646 manual opening model or the VCS 4646 solar opening model.

What is the internal glass size?

The visible internal glass size is approximately 1181 x 1181mm.

How heavy is the FCM 4646?

The approximate skylight weight is 41.91kg excluding flashing. Lifting access, roof access and safe handling should be planned before installation.

Do I need custom flashing?

Yes, custom flashing is required and sold separately. The correct flashing depends on roof type, profile, pitch, water flow direction and kerb detail.

Which rooms suit this size?

The FCM 4646 is well suited to living rooms, kitchens, dining areas, large bathrooms, stairwells, studios, open-plan extensions and feature daylight zones.

Can this replace an old acrylic dome skylight?

It can suit selected replacement projects, especially where the existing opening and kerb are compatible, but the roof opening, throat size, kerb size and roof condition must be checked first.

Can Central Skylights install it?

Central Skylights can help with supply-only, pickup, delivery or full Melbourne installation depending on your roof type, access, location and project requirements.

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